Farseer Meter/Pixel Ratio

I've done a lot with box2d in c++, and am giving C# a try. It looks like Farseer is generally used in place of Box2D (I'm aware of Box2DXNA, but it seems a little outdated.) So, Farseer is what I've been using. When I was using C++ and Box2D,
everyone always advised against using a 1pixel/meter ratio (For what reason, I don't know,) and usually suggested using somewhere around 30pixels/meter. As I've been researching Farseer, I've seen a lot of conflicting statements. Some say to use 1pixel/meter,
others say to use a scale, others say to use ConvertUnits.ToSimUnits and ConvertUnits.ToDisplayUnits, etc.

So what should I use? Right now, I'm using ConvertUnits, but everything renders in weird places. Is there a de-facto standard or anything that I should go by? Thanks in advance.